Noun:
1. A homosexual male.
2. A straight man who humps a homosexual man in the butt- not because he's gay, but because he's just desperate to get his rocks off. The Rainbow Rammer in this case would signify the "giver", not the "taker". The receiving person would be known as the "Rammee".
3. A far more colorful way to call someone stupid. (Simply replace the word "gay" with "rainbow rammer" in your day-to-day conversations)
A bisexual man who doesnt only slide it in but automatically starts ramming it hard inside the man or woman very hard until possible bleeding if not bad bruising.
Girl: owww! owww! stop being a rectum rammer you arehurting me!
Man: I cant baby it feels so good! *WHAM WHAM WHAM WHAM WHAM!!*
A twenty-something male that enjoys digging up dead bodies, connecting the rectum to the penile canal by using a power drill, and then finally inserting a frog or toad into the anus and pushing it through the urethra using a blunt stick. The frog or toad is then released back into it's home body of water to share it's experiences.